DEV002402 Supplementary Material

Files in this Data Supplement:

• Supplemental Figure S1 -

  Fig. S1. Variability of developmental stages in littermate embryos at 9.5 dpc in the CD1 background. (A-D) Littermate embryos obtained from heterozygous Sema3a-null mice in the CD1 background were stained with the blood vessel marker endomucin and examined by laser scanning confocal microscopy. (A,B) Wild-type littermate embryos of the same gestational age, 9.5 dpc, at a different developmental stage, as determined by somite(s) number. Head vessels (arrowheads) in the more mature embryo (24 somites, A) appeared more complex than in the less mature embryo (19 somites, B). A paired anterior cardinal vein (acv), a paired dorsal aorta (da) and intersomitic vessels (arrows, A-D) were always seen in 9.5-dpc embryos. Intersomitic vessels had branched in the 24-somite embryo (curved arrow in A,C), but not in the less mature embryo (Δ in B,D).

• Supplemental Figure S2 -

  Fig. S2. Whole-mount PECAM staining of 9.5-dpc embryos is not a robust method to detect the anterior cardinal vein. (A,B) 9.5-dpc wild-type CD1 embryos were stained with antibodies to PECAM and photographed using a camera attached to a conventional light microscope. The anterior cardinal vein (acv) with several venous sprouts (arrowheads) was detectable on the left side next to the otic vesicle (ov), but not on the right side of the same embryo. By contrast, the dorsal aorta (da) was visible on both sides.